Ring binder



J n 2 1943- c. D. TRUSSELL RING BINDER.

Filed Jan. 25, 1943 INVENTOR (Zn/Fewer. firussiu BY 2 A'T llgmim Patented June 29, 1943 2,323,285 1 RENG BINDER Clarence D. Trussell, Poughkeepsie, N. Y.,' assign or to Trussell Manufacturing Company, Poughkeepsie, N. Y., a corporation'of New York Application January 25, 1943, Serial No. 473,558

1 Claim.

The invention here disclosed relates to ring binders and is a continuation in part of the invention disclosed in copending patent application, Ser. No. 467,641 filed Dec. 2, 1942.

Special objects of the present invention are to provide an improved back construction, in which the rings can be smoothly and easily engaged and be readily released and which will firmly hold the rings when engaged therewith and which back construction, with these and other advantages will be simple in structure, low in cost, easy to manufacture and practical and efficient in all respects.

The foregoing and other desirable objects are attained by novel features of construction, combinations and relations of parts, all as hereinafter described, illustrated by way of example in the accompanying drawing and covered in the claim.

Figs. 1 to 4 in the drawing are broken sectional views illustrating successive steps in the formation of the so-called keyhole slots utilized for removably securing the binder rings in the back piece; Fig. 1 illustrating the step of drilling the entrance opening, Fig. 2 illustrating the undercutting and Figs. 3 and 4 illustrating the burnishing operations.

Fig. 5 is a broken plan view of the finished back piece.

Fig. 6 is a broken cross-sectional view of a finished binder having the back piece incorporated therein.

As shown more fully in Figs. 5 and 6, the back of the binder consists in the present invention of a strip of wood I, substantially triangular in cross-section, providing the convergently inclined fiat upper faces 8, 9, and having keyhole slots I0, to receive and releasably secure the ends of the binder rings I I.

In the special method of manufacture here disclosed, the retaining slots are formed by first drilling in a ring end receiving opening I2, at one side of the ridge or crest I3, of the strip, with a drilling and undercutting tool I4, Fig. 1, and then relatively shifting the work and the tool to form the groove I5, extending from the bottom of the opening and to rout out the narrow slot I6, and leave the flanges IT, at the opposite edges of the same.

The cutting tool I4, may be a fly cutter, sharpened along both edges and notched in opposite sides as indicated at I8, to cut out the narrow slot I6, and to leave the overstanding ledges II, connected about the end of the narrow slot as at I9, in Fig. 2.

ill

After completing the drilling, transverse grooving andundercutting operations illustrated in Fig. 2, the tool and work are returned to the Fig. 1 position and the tool withdrawn through the first cut, to leave the complete undercut keyhole slot.

The ledges or flanges about the narrower portions of the slots form the means for confining the ring ends, Fig. 6, showing how the stem portions of th rings are grooved at 20, at opposite sides to engage over these ledges. To provide a proper fit, it is important that these ledges be of a definite thickness and to assure the ready engagement and disengagement of the rings in respect thereto, it is important that these ledges be smooth, hard surfaced and of substantially uniform thickness their full extent.

To obtain these results, the ledges are finished, in the present disclosure with a rotary burnishing tool, such as indicated at 2|, Fig. 3, having a head portion 22, to finish the walls of the entrance opening I2, and undercut portion I5, and grooved at 23, to compress and smooth the rounded edge portions of the ledges and to actually reduce them to a lesser, uniform thickness as indicated at 24, Figs. 5 and 6.

This burnishing tool, shaped to closely fit the walls left by the cutting tool and rotating at high speed, compresses, smoothes and hardens the surfaces, levelling off inequalities that may be left by the cutting tool and, in tapering the edge portions .of the ledges, accurately sizes and gives them a permanent set as well as reinforcing by stiffening them. The heat and pressure from the burnishing tool, in effect, applies a hardened or harder surface layer over the walls of the cavity and in particular about the edges of the overstanding flanges.

The wooden back may be left plain or be painted, stained or otherwise finished. At present, it is preferred to give it a coating of varnish or shellac.

The drilling, undercutting and burnishing operations may be carried out either before or after any such finishing or coating of the back piece.

In practice, where shellac is used as a coating I ledges, which materially contributes to the" smooth action of engaging and disengaging the ring ends.

To further facilitate the free action of the ring ends in the confining slots, the walls defining these slots and particularly the surfaces of the confining ledges may be treated with a surfacing medium such as wax or grease. A composition of ground mica and grease has been found particularly desirable, enabling smooth sliding action in engaging and disengaging the ring ends.

The various operations above may be performed on the back material while it is in a continuous strip form or may be carried out on sections of the strip which have been cut to the desired binder lengths. The operations are relatively simple and may be performed on fully automatic or partly automatic machines. Such machines may be of the multiple spindl type designed to form or finish any desired number of keyhole slots at a time.

Fig. 6 shows how the back piece when made with a substantially fiat base 25, may be secured as by rivets or other fastening medium 26, directly to the back of the cover 21.

What is claimed is:

Awooden binder back having oppositely disposed transversely extending slots undercut toward the outer ends of the same to form opposed ring retaining flanges and enlarged at the inner ends of said flanges, said flanges being compressed. over the upper and lower faces and about the edges of the same to substantially uniform thickness, firmness and smoothness.

CLARENCE D. TRUSSELL. 

